The present invention relates to fiber-reinforced rubber products, fiber reinforcements for such products and processes for manufacturing such reinforcements.
Molded rubber products such as tires and hoses often contain polyamide fiber reinforcement. The fiber, usually in the form of a cord, is typicallY prepared by coating the cord with an adhesive, such as resorcinol formaldehyde latex (RFL) composition. The coated cord may be subsequently heat-treated to cure the adhesive. The resultant coating provides adhesion of the cord to the rubber. The cord is subsequently combined with uncured rubber and the rubber is steam cured.
It has been found that the cord loses significant strength when it is coated with an adhesive and then heat-treated. An object of the present invention is to reduce the amount of strength loss in the fiber intended for reinforcement of rubber after coating with adhesive.